This invention relates in general to vehicle hubs and in particular to an improved ductile iron vehicle hub and method for producing the same. A typical vehicle hub is formed from either ductile iron or aluminum. A ductile iron hub has increased tensile and yield strengths compared to those of an aluminum hub. However, the weight of the ductile iron hub is substantially greater than that of a similar sized aluminum hub. In order to reduce the weight of a ductile iron hub, it is known to subject the ductile iron hub to an austempering heat treatment process. While the cost of an austempered ductile iron hub is comparable to that of an aluminum hub, the austempering heat treatment process increases the costs of the austempered ductile iron hub compared to that of a conventional ductile iron hub.
The tensile and yield strengths of an aluminum hub are not as great as that of a similar sized conventional or austempered ductile iron hub. As a result, thicker sections are required in an aluminum hub compared to that in a ductile iron hub, especially compared to that in an austempered ductile iron hub. Unfortunately, the thicker sections in the aluminum hub take up more space and therefore, leave less space for certain components of the vehicle, such as the vehicle brake assembly. Thus, it would be desirable to provide a improved ductile iron hub and method for producing such a hub which is comparable in weight to a similar sized aluminum hub and/or austempered ductile iron hub, less expensive to manufacture compared to a similar sized austempered ductile iron hub, and has tensile and yields strengths which are similar to those of a similar sized austempered ductile iron hub.